Twitter sent out a very strange email to all of its users over night about a few important changes the company is making, including the switch to OAuth that broke many users' third party Twitter apps yesterday.

What makes the email so strange?

It refers to the changes as happening "over the coming weeks," and talks about August 31 as a date in the future. We received the email after 5 am today, September 2, and we can't find reports of anyone getting it more than a few hours ago.

Why does this matter?

Aside from simply being weird, the timing is a big deal because when Twitter switched to requiring OAuth, any third-party app that wasn't equipped for this simply stopped working, often without explanation. The change has been in the works for a long time now, so all major app developers had released versions of their products that handled the change without an issue, but users who hadn't updated their apps, including our own Henry Blodget, were confused and angry.

We've asked Twitter for a clarification on the timing of the email.

The other announcement is also old news to those that read the company's blog, but presumably new to most users: Twitter will be wrapping all links posted through the service with links from its own t.co domain. On mobile devices, users will see shortened t.co links, much like the third-party shortened (think bit.ly) links you see on Twitter now. Users on computers will see the full, original domain name of the link, and a shortened version of the rest of the URL, so they know if they are clicking on a trusted site. Only the shortened version of the link will count against the user's 140 character limit.

That means three things:

Twitter will be able to track all links and clicks through its service, allowing to offer -- and charge for -- analytics.

Using generic third-party URL shorteners will still work, but will be counter-productive. Twitter will rewrap the links, so both it and the third-party will be able to track it. But it will be displayed as shortened gibberish, which will no longer be necessary.

That's not an immediate deal-breaker for shorteners, like bit.ly, that make their real money providing branded shorteners to publishers, since users will still know what they are clicking on when they see, say, our read.bi links. But the value of them will certainly be diminished, and Twitter could soon be competing directly with them providing link tracking analytics.

The new t.co links will start rolling out in the coming weeks, and are expected to hit all users by the end of the year.